Applicability of Prediction Rules in Patients With Community-Acquired Pneumonia Requiring Intensive Care: A Pilot Study

CURB-65, PSI, and APACHE II to Assess Mortality Risk in Patients With Severe Sepsis and Community Acquired Pneumonia in PROWESS

Background: Patients with community-acquired pneumonia (CAP) comprised 35.6% of the overall phase 3 Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis (PROWESS) study and 33.1% of the placebo arm. We investigated the use of CURB-65, the Pneumonia Severity Index (PSI), and Acute Physiology and Chronic Health Evaluation II (APACHE II) prediction scores to identify the CAP population from the PROWESS placebo arm at the greatest mortality risk. Methods: Patients were classified as having CAP if the lung was the primary infection site and the patient originated from home. The abilities of CURB-65, PSI, and APACHE II scores to determine the 28-day and in-hospital mortality were compared using receiver operator characteristic (ROC) curves and the associated areas under the curve. Results: PROWESS enrolled 278 patients with CAP in the placebo arm. The areas under the ROC curves for PSI = 5, CURB-65 ≥3, and APACHE II ≥25 for predicting 28-day (c = 0.65, 0.66, and 0.64, respectively) and in-hospital mortality (c = 0.65, 0.65, and 0.64, respectively) were not statistically different from each other. The 28-day mortality of patients with a PSI score of 5, CURB-65 ≥3, and APACHE II ≥25 was 41.6%, 37.9%, and 43.5%, respectively. Conclusions: Despite early diagnosis and appropriate antibiotic therapy, conventionally treated CAP with PSI = 5, CURB-65 ≥3, or APACHE II ≥25 has an unacceptably high mortality. In this study, PSI, CURB-65, and APACHE II scoring systems perform similarly in predicting the 28-day and in-hospital mortality; however, differences in the categorization of severe CAP were observed and there was a significant mortality in patients with a CURB-65 <3 and PSI <5.

Severity of illness scoring systems in patients with bacteraemic pneumococcal pneumonia: implications for the intensive care unit care

Severity of illness scoring systems are useful for decisions on the management of patients with community-acquired pneumonia (CAP), including assessing the need for intensified therapy and monitoring, or for intensive care unit (ICU) admission. We compared the accuracy of the Pneumonia Severity Index (PSI), the CURB-65 and CRB-65 score, the modified-American Thoracic Society score (ATS), the IDSA/ATS guidelines and the Pitt Bacteraemia score (PBS) in evaluating severity of illness in 766 patients with bacteraemic pneumococcal pneumonia. We evaluated the sensitivity and specificity, the positive predictive value (PPV) and the negative predictive value (NPV) and the accuracy of the classification in predicting 14-day mortality. The PSI and the IDSA/ATS guidelines were the most sensitive whereas the PBS and modified-ATS scoring systems were the most specific in predicting mortality. The NPV was comparable for all four scoring systems (all above 90%), but the PPV was highest for PBS (54.2%) and lowest for PSI (23.2%). The predictive accuracy and discriminating power as measured by the receiver-operating characteristic (ROC) curve was highest for the PBS. Both the modified-ATS and the PBS scoring systems identified those patients who might benefit most from intensified care and monitoring. The PBS and modified-ATS proved superior to the IDSA/ATS guidelines, CURB-65 and CRB-65 with respect to their specificity and PPV. The low PPV of the PSI rendered it not usable as a parameter for decision-making in severely-ill patients with pneumococcal bacteraemia.

Clinical review: mass casualty triage--pandemic influenza and critical care

Worst case scenarios for pandemic influenza planning in the US involve over 700,000 patients requiring mechanical ventilation. UK planning predicts a 231% occupancy of current level 3 (intensive care unit) bed capacity. Critical care planners need to recognise that mortality is likely to be high and the risk to healthcare workers significant. Contingency planning should, therefore, be multi-faceted, involving a robust health command structure, the facility to expand critical care provision in terms of space, equipment and staff and cohorting of affected patients in the early stages. It should also be recognised that despite this expansion of critical care, demand will exceed supply and a process for triage needs to be developed that is valid, reproducible, transparent and consistent with distributive justice. We advocate the development and validation of physiological scores for use as a triage tool, coupled with candid public discussion of the process.

Prognostic scoring systems: which one is best?

PURPOSE OF REVIEW

In the initial evaluation of patients with community-acquired pneumonia, a number of important assessments are made, including that of the severity of the illness. This assessment will determine the appropriate site of care, diagnostic work-up, and choice of empiric antibiotics. A number of severity assessment tools have been developed and some of the recent findings are reviewed.

RECENT FINDINGS

A number of studies of the efficacy of the individual scoring systems, as well as comparator studies, have been undertaken. A significant number of patients with community-acquired pneumonia in Pneumonia Severity Index classes I and II are admitted to hospital and several of these patients suffer complications. Clinical and social factors other than those contained in the scoring systems need to be taken into consideration when deciding about hospitalization of patients with community-acquired pneumonia. A number of studies of the efficacy of the various scoring systems in predicting 'severe pneumonia' have been undertaken, as well as studies of their accuracy in the sub-set of patients with pneumococcal infections and in the elderly.

SUMMARY

The various scoring systems have reasonable sensitivity and specificity and their own strengths and weaknesses, but should always be used in association with good clinical judgment.

Community-acquired pneumonia requiring admission to an intensive care unit: a descriptive study

Severe community-acquired pneumonia (CAP) requiring admission to an intensive care unit (ICU) has been inadequately studied. We compared characteristics and outcomes of patients with CAP who were admitted to the ICU with those of patients managed on the ward. Of the 3675 patients hospitalized with CAP, 374 (10%) were admitted to the ICU. The main reason for ICU admission was respiratory failure requiring intubation and ventilation (n = 303, 81%), although this indication decreased with increasing age (p < 0.05 for trend). Most patients (62%) required mechanical ventilation for 3 days or less. The following factors were predictive of ICU admission on multivariable analysis: younger age, smoker, limitation of functional status, absence of cough or pleurisy, presence of chronic obstructive pulmonary disease, substance abuse, elevated serum creatinine, abnormal serum glucose concentration, and a respiratory rate of <16 or >24 breaths per minute. Patients with low Pneumonia Severity Index scores and low CURB-65 scores were admitted to the ICU based on clinical judgment that appeared to supersede objective scoring. Severe CAP requiring admission to the ICU is common, and the decision about which patients to admit often requires clinical judgment that in many cases appears at odds with various validated pneumonia severity scoring systems.

Évaluation des soins et pneumopathies aiguës communautaires

INTRODUCTION

Evaluations of care strategies for patients with community acquired pneumonia (CAP) tend to focus more on their necessity (variation in practice...) than on efficacy (adherence, impact of markers of disease severity or medico-economic factors...).

STATE OF THE ART

A number of studies are reported in the literature based on a simple evaluation of practice at a given moment on time or else on the impact of guidelines. These evaluations relate either to outcome criteria (mortality, and duration of stay especially) or the economic impact of CAP (rate of hospitalization, duration of stay, costs of the treatments or hospitalizations...), or on process of care (evaluation of initial severity, delay in administration of antibiotics, appropriateness of antibiotic therapy, evaluation of oxygenation and taking of specimens prior to treatment).

PERSPECTIVES AND CONCLUSIONS

Taken together these studies demonstrate the need to improve and standardise care. Where studies have not found a benefit from guidelines this can often be attributed to problems with assessment or study design and there are many studies showing the benefit of guideline based management and the introduction of standardised care pathways.